磁共振扩散张量成像在急性脑梗死诊治中的应用

Application of magnetic resonance diffusion tensor imaging in diagnosis of acute cerebral infarction

目的探讨磁共振扩散张量成像(DTI)在急性脑梗死诊治中的应用。方法对22例急性脑梗死患者脑卒中发生6~24h内行DTI序列扫描。感兴趣区设定在梗死区中心、边缘及灶周正常区,用镜像的方法测定两侧对称的各感兴趣的各向异性分数(FA)值和平均扩散系数(DCavg)值,得到FA图和DCavg图,之后重建得到皮质脊髓纤维束图。结果急性脑梗死病灶在T2WI、FLAIR、DWI图像上均显示高信号;在FA图上显示稍低信号;在彩色编码的FA图中,梗死区域的纤维束颜色、方向部分混杂,病灶侧与镜像侧不对称。病变侧梗死区中心、边缘的FA和DCavg值与镜像侧对称区域的FA和DCavg值进行比较,差异均有统计学意义(均P<0.05)。病变侧梗死区中心、边缘与灶周正常区的FA、DCavg值比较,差异有统计学意义(均P<0.01),其中梗死区中心与边缘比较差异均无统计学意义(均P>0.05)。结论 DTI技术能为急性脑梗死的诊断、预后判断提供重要信息,以更好地确定治疗计划。

Objective To evaluate the application of magnetic resonance diffusion tensor imaging（DTI） in diagnosis of acute cerebral infarction. Methods DTI sequence scan was performed on 22 patients with acute cerebral infarction at 6-24 h after onset. Region of interest（ROI） was set in the center, peripheral parts of lesion and normal parts around lesion, and the symmetrically anisotropic fraction（FA） value and the average diffusion coefficient（DCavg） value were measured using a mirror image method, and FA map and DCavg map were obtained. Then the corticospinal tract map was reconstructed. Results The acute cerebral in farcted area showed a high signal on T2 WI, FLAIR, and DWI images, and a slightly lower signal in the FA map. In the color-coded FA map, the direction and color of the fibers in the lesion were slightly mixed, and bilateral asymmetry. The FA and DCavg values at the center and peripheral parts of lesion were statistically different from those at the mirror side（all P〈0.05）.The differences of FA and DCavg values at the lesion side between the center, peripheral parts of lesion and normal parts around lesion were statistically significant（all P〈0.01）, and there was no significant difference between central of lesion and peripheral parts of lesion（all P〈0.05）. Conclusion DTI technique provides important information for the diagnosis and prognosis of acute cerebral infarction, which facilitate the determination of treatment plan for patients.